Lack of Sleep can result in Obesity | Latest Studies Shows!

Can lack of sleep holds potential to make you fat? There are multiple research papers that answers this question. These papers have analyzed the evidence from the self-reported sleep deration studies aligned with sleep restriction studies (reported by participants) and points their finger towards the confirmation. They claim that sleeping less that 7 hrs. can cause obesity.

The research paper published by American Journal of Human Biology in 2012, Journal of Clinical Endocrinology & Metabolism 2020, National Health and Nutrition Examination Survey (NHANES) 2021 and in BMC Public Health 2020, provide us the relationship between sleep and obesity.

In this article we are going to brief you about the finding of these research papers and will reach on a conclusion, about the right duration of sleeping.

American Journal of Human Biology in 2012

The research paper published by American Journal of Human Biology in 2012 was under Dr. Kristen Knutson, from the university of Chicago. The study after analysis shows the strong connection between lack of sleep and obesity. A review of the evidence shows how short or poor-quality sleep is linked to increased risk of obesity by de-regulating appetite, leading to increased energy consumption.

Obesity develops when energy intake is greater than expenditure. Diet and physical activity play an important part in this, but an additional factor may be inadequate sleep,” said Dr Kristen Knutson, from the University of Chicago.

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Here are some key findings about the research paper:

When we don’t get enough sleep, our bodies become confused. They mistakenly believe they are low on energy, which can lead to increased appetite. This can cause us to eat more than we need, especially foods that are high in calories and unhealthy fats.

Observational Studies Findings

  • People who get fewer than six hours of sleep tend to have a higher body mass index (BMI) or obesity.

Impact of Sleep on Appetite Regulation

  • Experimental studies showed that lack of sleep affects the brain’s signals for controlling appetite.
  • Sleep deprivation affects the hormones ghrelin (which makes you hungry) and leptin (which tells you when you’re full).
  • This can lead to eating more without burning enough energy. Studies show that sleep is crucial for regulating metabolism. Without enough sleep, your body may burn calories less efficiently.
  • The body seeks a quick energy boost, leading to cravings for unhealthy choices. Fatigue can make us less likely to exercise, a crucial factor for weight management.

Prevalence of Inadequate Sleep

  • In the United States, about 18% of adults get less than six hours of sleep, which is around 53 million people.
  • Understanding the reasons behind poor sleep is crucial to identify at-risk groups.
Effect on Different Age Groups and Socioeconomic Status
  • The link between lack of sleep and higher BMI is stronger in children and teenagers.
  • People from lower socioeconomic backgrounds may face higher risks of obesity due to sleep deficiency.

Geographical Variation in Research

  • Most studies Dr. Knutson reviewed were from Western countries, showing a need for more research globally.
  • Some studies in the special issue focused on obesity in the United Arab Emirates, Samoa, and Brazil.

Implications and Future Research

  • Poor sleep increases the risk of obesity, diabetes, high blood pressure, and heart disease.
  • Further research should explore if improving sleep can help prevent or manage these health conditions.


  • Dr. Knutson’s research highlights the critical link between inadequate sleep and obesity-related health risks, emphasizing the importance of understanding and addressing sleep patterns to improve overall health outcomes.
  • Getting enough sleep is vital for maintaining a healthy weight. By understanding the hormonal and metabolic effects of sleep deprivation, we can make informed choices about our sleep hygiene to promote overall well-being.

Journal of Clinical Endocrinology & Metabolism 2020

The article published in the Journal of Clinical Endocrinology & Metabolism in 2020 highlights the potential causes and effect about the relationship between sleep and obesity. Lack of sleep can cause trouble for our hormonal balance, leading to psychological and appetite changes. These problems can further confer to promote weight gain, while obesity itself can contribute to sleep problems like sleep apnea.

Aim of the Article

  • It sheds the lights on the possibility that sleep restriction can lead to physiological and hormonal changes that promote weight gain. Conversely, the article also explore that how obesity itself can contribute to sleep problems like sleep apnea.

Findings of the study

  • Sleep Deprivation Impacts Hormones: Lack of sleep disrupts the production of hormones that regulate hunger and fullness, potentially leading to overeating.
  • Hormonal Imbalance and Weight Gain: This imbalance can contribute to weight gain over time.
  • Obesity Worsens Sleep: Obesity itself can worsen sleep problems like sleep apnea, which further disrupts sleep quality.
  • Poor Sleep Perpetuates the Cycle: Poor sleep quality can then perpetuate the hormonal imbalance, potentially leading to continued overeating and weight gain.

National Health and Nutrition Examination Survey (NHANES) in 2021

This was a cross-sectional study, meaning it captured data at a single point in time. While it can identify associations between variables (sleep duration and weight), it cannot definitively prove cause and effect. The research team used data from the National Health and Nutrition Examination Survey (NHANES), a large-scale program by the Centers for Disease Control and Prevention (CDC) that collects health and nutritional information from a representative sample of the US population.


  • Researchers looked at self-reported sleep duration (reported by participants) and categorized them into three groups:
    • Short sleep: Less than 7 hours per night
    • Normal sleep: 7 to 9 hours per night
    • Long sleep: More than 9 hours per night
  • They then compared these sleep duration groups with body mass index (BMI) to assess the risk of overweight and obesity.
Key Findings:
  • Adults who slept less than 7 hours per night (short sleep) were significantly more likely to be overweight and obese compared to those who slept 7 to 9 hours.
  • Interestingly, adults who slept more than 9 hours per night (long sleep) were also found to have a higher risk of obesity compared to the normal sleep group.
  • The study also explored potential differences by sex and age, finding that the association between short sleep and obesity was stronger in females younger than 65 years old.


  • As with most cross-sectional studies, this research cannot establish cause-and-effect. It’s possible that other factors like underlying health conditions or socioeconomic status might influence both sleep duration and weight.
  • Sleep duration was based on self-reported data, which can be prone to bias.

Overall Significance:

This study adds to the growing body of evidence suggesting a link between sleep duration and weight status. It highlights the importance of getting optimal sleep (around 7-9 hours for adults) for maintaining a healthy weight.

Concluding Above Studies | How Much Sleep Do We Need?

Above you have seen multiple research papers and articles, each have their own way to reach at conclusion and proclaiming the relationship between sleep and obesity. Some papers have used self-reported sleep duration strategy, some used sleep-restriction strategy and some research are confined to a certain region only. Despite all these differences, they all reach on the same conclusion, that is lack of sleep can result in obesity. Moreover, over sleeping can also cause obesity. Nevertheless, obesity can cause lack of sleep too. So it will became an endless loop. Therefore we need to manage our sleeping duration-

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The amount of sleep a person needs varies depending on their age. Here’s a general guideline:

  • Elementary school students (5-10 years old): 8-12 hours
  • Middle school students (11-14 years old): 6.5-10 hours
  • Most adults (18-64 years old): 7-8 hours

By getting enough sleep, we can help regulate our hormones, keep our appetite in check, and maintain a healthy metabolism – all of which are important factors in maintaining a healthy weight.

Frequently Asked Questions

Here are some frequently asked questions

Why does lack of sleep lead to obesity?

Lack of sleep contributes to obesity in a few ways:

  • Hormonal Imbalance: Sleep deprivation disrupts the production of leptin (the “I’m full” hormone) and ghrelin (the “I’m hungry” hormone). This can lead to increased hunger and cravings, especially for unhealthy, high-calorie foods. You might end up eating more than you need, promoting weight gain.
  • Decreased Metabolism: Studies suggest sleep is crucial for regulating metabolism, the process your body uses to convert food into energy. When you don’t get enough sleep, your metabolism may slow down, making it harder to burn calories efficiently. This can hinder weight loss efforts.
  • Reduced Motivation for Exercise: Fatigue caused by sleep deprivation can zap your motivation to exercise, a crucial factor for weight management. You might be less likely to engage in physical activity that helps burn calories and manage weight.

What are the effects of lack of sleep?

Lack of sleep has various negative effects beyond weight management, including:

  • Decreased Cognitive Function: Sleep deprivation can impair memory, focus, and concentration.
  • Mood Changes: Lack of sleep can increase irritability, anxiety, and symptoms of depression.
  • Weakened Immune System: Sleep is essential for immune function, and not getting enough sleep can make you more susceptible to illness.
  • Increased Risk of Chronic Diseases: Studies suggest a link between chronic sleep problems and an increased risk of conditions like heart disease, diabetes, and high blood pressure.

How does lack of sleep affect fat loss?

By creating hormonal imbalances and potentially increasing calorie intake, lack of sleep can make it more challenging to lose fat. Decreased metabolism due to sleep deprivation can hinder your body’s ability to burn calories efficiently. This can make it harder to create a calorie deficit, which is necessary for fat loss.

Does late night sleep cause obesity?

The research suggests it’s not just about the total sleep duration, but also about consistency. Regularly going to bed late and disrupting your sleep cycle can have similar negative effects on hormones and metabolism as not getting enough sleep overall. A disrupted sleep schedule can create similar challenges for weight management as chronic sleep deprivation.

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